unload-1.html
<!doctype html>
<html>
<head><title>Document</title></head>
<body>
<h1>Document</h1>
<script>
onload = function() {
document.addEventListener("visibilitychange", onVisibilityChange, false);
opener.postMessage("close", "*");
}
function onVisibilityChange() {
opener.postMessage(document.visibilityState, "*");
}
</script>
</body>
</html>